JPS6143142B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic vibration mold for continuous casting.

BACKGROUND ART Conventionally, an ultrasonic vibrator is attached to a mold of continuous casting equipment to perform casting while vibrating the mold to prevent molten steel from seizing on the inner surface of the mold.

However, conventional ultrasonic vibration molds for continuous casting use only either longitudinal waves or transverse waves among the waves (vibration waves) generated on the mold wall, so the antinodes and nodes of the vibration are at fixed positions on the mold wall. As a result, the amplitude is 0 at the node position, so
The relative velocity between the molten steel and the mold wall in this part became 0, and there was a risk that the molten steel would seize at the joint position.

In order to solve the above-mentioned problems, the inventors of the present application have conducted various studies and found that by using an ultrasonic vibrator attached to the mold, the mold can generate extremely complex vibrations that combine longitudinal waves and transverse waves. However, we have discovered that by using both of these vibration waves, it is possible to vibrate the mold efficiently.

The present invention has been made based on the above findings, and includes a plurality of ultrasonic transducers installed at right angles at intervals on the outer surface of the inner wall of a continuous casting mold, and in which a plurality of ultrasonic transducers are attached at right angles to each other at intervals. The length is set to such a length that the ultrasonic vibrator causes the mold to resonate in the slab drawing direction and the direction orthogonal to the slab pulling direction, and the ultrasonic vibrator The device is characterized in that it is attached so that the antinode of the vibration wave caused by the resonance is located at both ends.

The principle of this invention will be explained with reference to the drawings.

FIG. 1 is a diagram showing the relationship between the attachment position of the ultrasonic vibrator 2 to the mold 1 and the vibration waves of the mold 1.

Figure 1A shows longitudinal waves (waves that vibrate in the same direction as the slab pulling direction) generated in the mold 1 by the ultrasonic vibrator 2 A _and transverse waves (waves that vibrate in the direction perpendicular to the slab pulling direction) B FIG. 3 is an explanatory diagram showing a state in which ₀ occurs. Here, λ _A is one wavelength of longitudinal wave A ₀ , and λ _B is transverse wave
One wavelength of B ₀ is shown, and the ultrasonic transducer 2 is connected to the mold 1.
It is attached at a position of λ _A /4 from the end of.
The wavelength λ _B of the transverse wave B ₀ generated simultaneously with the longitudinal wave A ₀ by the ultrasonic transducer 2 is λ _B =λ _A /2. In this case, the mounting position of the ultrasonic transducer 2 is expressed as λ _B , which is a position λ _B /2 from the end of the mold 1.

FIG. 1B shows the mounting position of a conventional ultrasonic transducer on a mold, corresponding to FIG. 1B. That is, in Figure B, A ₁ indicates the attachment position of the ultrasonic vibrator to the mold 1 when focusing on longitudinal waves, and it is attached at the node position A ₀ in Figure A. On the other hand, in diagram B, B ₁
1 shows the mounting position of the ultrasonic transducer on the mold 1 when focusing on transverse waves, and it is mounted at the antinode of B ₀ in Fig. A. Note that a and b indicate oscillators whose phases differ by 180°, respectively.

Therefore, if the ultrasonic vibrator 2 is installed at the position where a and b match in A ₁ and B ₁ in the diagram, both longitudinal and transverse waves can be efficiently used to vibrate the mold 1. can. The attachment position of the ultrasonic transducer 2 to the mold 1 in this case is shown in FIG. 1C. In A ₁ of Figure B, ultrasonic transducer b installed to excite the vibrations caused by ultrasonic transducer a, in B ₁ of Figure B, acts to cancel the transverse waves, resulting in a decrease in efficiency. I understand that.

In other words, from Figure C, the ultrasonic transducer 2 should be attached to the mold 1 at an interval of λ _A from λ _A /4 from the end of the mold 1, and the ultrasonic transducer should be installed at the same position. I understand that. That is, if the ultrasonic vibrator 2 is attached at a position of λ _A /4 + λ _A × m (m is 0 or a positive integer) from the end of the mold 1, the ultrasonic vibrator 2
It is possible to obtain an ultrasonic vibration mold that efficiently utilizes longitudinal waves and transverse waves.

In addition to the combination shown in Figure B, the combination shown in Figure 1D is also conceivable. This is A ₂ (installation position of the ultrasonic transducer to mold 1 when focusing on longitudinal waves) and B ₂ in Figure 2.
(The attachment position of the ultrasonic transducer to the mold 1 when focusing on transverse waves), the position where a and b match, that is, 3/4λ _A +λ _A (m is 0 or positive) from the end of the mold 1. If the ultrasonic vibrator 2 is installed at a position (an integer of The attachment position of the ultrasonic transducer 2 to the mold 1 in this case is shown in FIG. 1E.

Figure 2 shows a case in which the ultrasonic transducer arrangement shown in Fig. 1 C is applied to a vertical continuous casting mold, and Fig. 3 shows a case in which the ultrasonic transducer arrangement shown in Fig. 1 E is applied to a vertical continuous casting mold. Further, FIG. 4 shows a case where the arrangement of ultrasonic transducers shown in FIG. 1C is applied to a horizontal continuous casting mold. In each figure, 3 indicates a tundish, 4 a nozzle, 5 a power source for the ultrasonic transducer 2, 6 a longitudinal vibration wave, and 7 a transverse vibration wave.

As explained above, according to the present invention, the longitudinal waves and transverse waves generated by the ultrasonic vibrator can be effectively used to vibrate the mold, so that the mold can be vibrated efficiently. effect is brought about.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between the attachment position of the ultrasonic transducer to the mold and the vibration waves of the mold, and Figures 2 to 4 are:
FIG. 2 is a sectional view showing a casting mode using the ultrasonic vibration mold for continuous casting of the present invention. In the drawings, 1...Mold, 2...Ultrasonic vibrator, 3...Tundish, 4...Nozzle, 5...Power source, 6...
Longitudinal vibration wave, 7...Transverse vibration wave.

Claims (1)

[Claims] 1. A plurality of ultrasonic transducers are installed at right angles at intervals on the outer surface of the inner wall of a continuous casting mold,
The length of the mold in the slab drawing direction is set by the ultrasonic vibrator to a length such that the mold resonates in the slab pulling direction and a direction orthogonal to the slab pulling direction, and An ultrasonic vibration mold for continuous casting, characterized in that the sonic vibrator is attached to both ends of the mold so that the antinode of the vibration wave caused by the resonance is located at both ends of the mold.